The trial of a journalist imprisoned on defamation charges has begun today in Niger.

Ibrahim Soumana Gaoh, the director of news weekly Le Temoin, or The Witness, was arrested on Sunday in the capital Niamey.

He is charged in connection with an article published on September 14, which implicated Niger's minister of communications in a financial scandal.

The article hinted that Mohamed Ben Omar was involved in a corruption scandal surrounding the privatization of the country's biggest telecoms company in 2001.

Gaoh been held at the city's central prison since his arrest at the weekend. If convicted, he could face a lengthy jail sentence.

Mohammed Keita of the New York-based Committee to Protect Journalists (CPJ) says he is worried about the freedom of the press in Niger.

"CPJ is extremely concerned about the unrelenting criminal prosecution of journalists investigating or reporting corruption and government mismanagement in Niger," he sais. "Ibrahim Soumana Gaoh happens to be the second journalist now in prison for reporting critically on government affairs."

Last month a constitutional amendment was passed in the West African country, which straddles the Sahara desert. It allows President Mamadou Tanjda to run for re-election for the rest of his life. It also permits him to tighten his grip on the country's independent press.

Keita says Gaoh is the second journalist to be imprisoned in Niger in recent months.

"The president has essentially tightened his grip on the press," he added. "The controversial constitutional amendment that was passed last month contained a provision that allowed the president to handpick the media regulators of the country, and this media regulator has the power to suspend media outlets. We've seen a crackdown on the press in the lead-up to the referendum where the president was - through this body - essentially silencing media outlets that were critical of his bid to amend the constitution."

In August Abdoulaye Tiémogo was sentenced to three months in prison for criticizing an arrest warrant.

Criminal libel accusations hang over at least three other journalists in Niger.